using System;
using System.Runtime.InteropServices;
using System.IO;

public class RawPrinterHelper
{
	// Structure and API declarions:
	[StructLayout(LayoutKind.Sequential, CharSet=CharSet.Ansi)]
		public class DOCINFOA
	{
		[MarshalAs(UnmanagedType.LPStr)] public string pDocName;
		[MarshalAs(UnmanagedType.LPStr)] public string pOutputFile;
		[MarshalAs(UnmanagedType.LPStr)] public string pDataType;
	}
	[DllImport("winspool.Drv", EntryPoint="OpenPrinterA", SetLastError=true, CharSet=CharSet.Ansi, ExactSpelling=true, CallingConvention=CallingConvention.StdCall)]
	public static extern bool OpenPrinter([MarshalAs(UnmanagedType.LPStr)] string szPrinter, out IntPtr hPrinter, long pd);

	[DllImport("winspool.Drv", EntryPoint="ClosePrinter", SetLastError=true, ExactSpelling=true, CallingConvention=CallingConvention.StdCall)]
	public static extern bool ClosePrinter(IntPtr hPrinter);

	[DllImport("winspool.Drv", EntryPoint="StartDocPrinterA", SetLastError=true, CharSet=CharSet.Ansi, ExactSpelling=true, CallingConvention=CallingConvention.StdCall)]
	public static extern bool StartDocPrinter( IntPtr hPrinter, Int32 level,  [In, MarshalAs(UnmanagedType.LPStruct)] DOCINFOA di);

	[DllImport("winspool.Drv", EntryPoint="EndDocPrinter", SetLastError=true, ExactSpelling=true, CallingConvention=CallingConvention.StdCall)]
	public static extern bool EndDocPrinter(IntPtr hPrinter);

	[DllImport("winspool.Drv", EntryPoint="StartPagePrinter", SetLastError=true, ExactSpelling=true, CallingConvention=CallingConvention.StdCall)]
	public static extern bool StartPagePrinter(IntPtr hPrinter);

	[DllImport("winspool.Drv", EntryPoint="EndPagePrinter", SetLastError=true, ExactSpelling=true, CallingConvention=CallingConvention.StdCall)]
	public static extern bool EndPagePrinter(IntPtr hPrinter);

	[DllImport("winspool.Drv", EntryPoint="WritePrinter", SetLastError=true, ExactSpelling=true, CallingConvention=CallingConvention.StdCall)]
	public static extern bool WritePrinter(IntPtr hPrinter, IntPtr pBytes, Int32 dwCount, out Int32 dwWritten );

	// SendBytesToPrinter()
	// When the function is given a printer name and an unmanaged array
	// of bytes, the function sends those bytes to the print queue.
	// Returns true on success, false on failure.
	public static bool SendBytesToPrinter( string szPrinterName, IntPtr pBytes, Int32 dwCount)
	{
		Int32    dwError = 0, dwWritten = 0;
		IntPtr    hPrinter = new IntPtr(0);
		DOCINFOA    di = new DOCINFOA();
		bool    bSuccess = false; // Assume failure unless you specifically succeed.

		di.pDocName = "My C#.NET RAW Document";
		di.pDataType = "RAW";

		// Open the printer.
		if( OpenPrinter( szPrinterName, out hPrinter, 0 ) )
		{
			// Start a document.
			if( StartDocPrinter(hPrinter, 1, di) )
			{
				// Start a page.
				if( StartPagePrinter(hPrinter) )
				{
					// Write your bytes.
					bSuccess = WritePrinter(hPrinter, pBytes, dwCount, out dwWritten);
					EndPagePrinter(hPrinter);
				}
				EndDocPrinter(hPrinter);
			}
			ClosePrinter(hPrinter);
		}
		// If you did not succeed, GetLastError may give more information
		// about why not.
		if( bSuccess == false )
		{
			dwError = Marshal.GetLastWin32Error();
		}
		return bSuccess;
	}

	public static bool SendFileToPrinter( string szPrinterName, string szFileName )
	{
		// Open the file.
		FileStream fs = new FileStream(szFileName, FileMode.Open);
		// Create a BinaryReader on the file.
		BinaryReader br = new BinaryReader(fs);
		// Dim an array of bytes big enough to hold the file's contents.
		Byte []bytes = new Byte[fs.Length];
		bool bSuccess = false;
		// Your unmanaged pointer.
		IntPtr pUnmanagedBytes = new IntPtr(0);
		int nLength;

		nLength = Convert.ToInt32(fs.Length);
		// Read the contents of the file into the array.
		bytes = br.ReadBytes( nLength );
		// Allocate some unmanaged memory for those bytes.
		pUnmanagedBytes = Marshal.AllocCoTaskMem(nLength);
		// Copy the managed byte array into the unmanaged array.
		Marshal.Copy(bytes, 0, pUnmanagedBytes, nLength);
		// Send the unmanaged bytes to the printer.
		bSuccess = SendBytesToPrinter(szPrinterName, pUnmanagedBytes, nLength);
		// Free the unmanaged memory that you allocated earlier.
		Marshal.FreeCoTaskMem(pUnmanagedBytes);
		return bSuccess;
	}
	public static bool SendStringToPrinter( string szPrinterName, string szString )
	{
		IntPtr pBytes = new IntPtr(0);
		Int32 dwCount;
		// How many characters are in the string?
		dwCount = szString.Length;
		// Assume that the printer is expecting ANSI text, and then convert
		// the string to ANSI text.
		pBytes = Marshal.StringToCoTaskMemAnsi(szString);
		// Send the converted ANSI string to the printer.
		SendBytesToPrinter(szPrinterName, pBytes, dwCount);
		Marshal.FreeCoTaskMem(pBytes);
		return true;
	}
}
